The invention concerns packaging for storing components of a multi-component adhesive stored separately from one another, in particular a three-component packaging for storing a mortar system based on a dual-hardening adhesive.
The use of reactive resin materials based on unsaturated polyester resins, vinyl esters, or epoxy resins as glues and adhesives for chemical fastening technology has long been known. These are two-component systems, one component containing the reactive resin, and the other component containing the hardening agent. Other usual components such as fillers, accelerators, stabilizers, and solvents including reactive solvents (reactive thinners) can be included in one and/or the other component. Then the reaction with the formation of a hardened product is set in motion by mixing the two components.
Usually, multi-component materials, such as, for example, mortar materials, foam materials, and sealing materials, are made available to the user as two-component or multi-component materials in cartouches, cartridges, and film-wrapped packs as injection systems. Film-wrapped packs have proved to be useful as packaging for such materials and, in particular, in comparison with cartridges, are characterized by the small amount of material that has to be discarded after the material is applied. In addition, film-wrapped packs are easy and economical to manufacture.
Basically, two systems are used in chemical fastening technology: one based on radically polymerizable, ethylenically unsaturated compounds, which as a rule are hardened with peroxides, and one based on an epoxy-amine system. The first system is characterized by rapid hardening, in particular at low temperatures such as −10° C., but has weaknesses in the load values. As opposed to this, the epoxy-amine systems do have a slower hardening rate, but are advantageous with respect to the load values and the robustness of the system.
Dual-hardening adhesives are being developed in order to combine the advantages of both systems. This means systems, the hardening of which takes place both radically and by polyaddition. These are also called hybrid systems or hybrid adhesives. These hybrid systems are based on resin compositions that contain compounds hardenable according to the first reaction type, for example, radically polymerizable compounds, and compounds polymerizable by polyaddition, for example epoxies, hardenable according to a second reaction type, different from the first reaction type. It is possible to harden a resin composition based on a radically polymerizable compound and an epoxy, for example, with a peroxide and an amine, it being possible for the radical hardening reaction to be accelerated with a transition metal compound.
A system of this kind is described in the unpublished application EP1021532.
However, systems that contain, in addition to the radically polymerizable part, a part that leads to a polyurethane or polyurea, such as, for example interpenetrating polymer networks (IPNs) based on polymethacrylates and polyurethanes, as glues and the like, also are known.
It is usual to divide two-component adhesives so that the resin component, which contains the reactive compound, if necessary, further additives and fillers, such as reactive thinners, inhibitors, accelerators, thickeners, thixotropic agents, and inorganic fillers, and the hardener component, which contains the hardening agent and, if necessary, further additives and fillers, such as thickening agents, thixotropic agents, phlegmatizing agents, and inorganic fillers, are packaged spatially separated so that a reaction takes place only when the two components are mixed with one another. In case of film bags used as packaging, the resin component is packaged in a first film bag and the resin component is packaged in a second film bag spatially separated from the first bag. This is similar to the situation for the cartridges also used, a smaller cartridge, which contains the hardener component, being located in a larger cartridge, which contains the resin component. In case of a cartouche as packaging, this usually contains two separate chambers, in order to achieve spatial separation of the components.
For a hybrid adhesive, as is described in the application EP10153243, in a usual two-bag injection system, the resin component, which is contained in a film bag, would contain the radically hardenable compound, the compound hardenable with an amine, catalysts, accelerator, if necessary reactive thinners, inhibitors, and a compound for bridge formation. Then the hardener component would contain the two hardening agents, the peroxide, and the amine.
Of course, this leads to some problems. On the hardener side, there is the problem that only a few peroxides and amine can be combined briefly storage-stable, that is, there is no flexibility with respect to the choice, in particular of the amine hardener for the epoxy resin. Further, it is not possible to ensure sufficient storage stability, even in case of those hardening agents that can be combined with one another. This invariably leads to an unpredictable impairment of the hardening and the performance of the adhesive, that is, the bonding strength of the anchoring elements.
However, on the resin side, problems based on reaction of the individual components with one another also can be expected.
Compounds that delay radical polymerization often are added to the resins or the resin components in order to make them storage-stable and/or to adjust the gel time. 4-hydrozy-2,2,6,6-tetramethyl piperidine-1-oxol (Tempol) is a common and proved compound. The literature (e.g. Sheldon et al., Org. Biomol. Chem., 2003, 1, 3232; E. G. Rozantsev et al., Russ. Chem. Rev., 1971, 40 (3), 233) contains information that Tempol reacts with Cu(I) and Cu (II) salts, which are used, among other things, as catalysts for the activation of the peroxide hardener in particular in the presence of atmospheric air. This decomposition reaction is also assumed for other stable nitroxyl radicals.
Thus, in case of packaging the package for hybrid adhesives, in particular according to EP10153243, it is necessary to pay attention to the fact that the following components may not be combined with one another, in order not to negatively influence either the storage stability or the hardening time, as well as the performance of the adhesive:                the peroxide and the amine,        the Tempol and the radically polymerizable compound,        the amine and the epoxy compound, and        the radically polymerizable compound and the amine.        
With respect to the packaging, the individual components must also be separated so that the required amount ratios, in particular the mixing ratio of hardenable compound to hardening agent, are maintained at the time of applying the adhesive, for example at the time of pressing out the individual components.
For the use on site, this means that the resin composition, the peroxide hardener, the amine hardener, as well as the accelerator must be kept spatially separated so that an unintended reaction, that is, either hardening of the resin composition or inactivation of the other components as described above, with one another is prevented. The difficulty now consists in packaging a multi-component, dual-hardening adhesive (hybrid adhesive) so that a reaction of the individual components with one another is prevented, and the adhesive can be easily used on site, for example in conventional glass or plastic cartridges or frequently used dispensing devices for two-component adhesives. Such a packaging is currently not known.
However, even in hybrid adhesives, that have a system that, for example, leads to polyurethanes or polyureas, instead of the epoxy-amine system, the individual components are not arbitrarily miscible, especially since amines also are required for systems with polyureas.